Signaling system for single-track railways.



S. N. WIGHT.

SIGNALING SYSTEM FOR SINGLE TRACK RAILWAYS.

APPLICAHON men 0156.1.1915.

1 ,300,081 Patented Apr. 8. 1919.

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A TTORIIVE Y UNITED STATES PATENT OFFICE.

SEDGWIGK N. WIGHT, OF ROCHESTER, NEW YORK, ASSIGNOR TO GENERAL RAILWAY SIGNAL COMPANY, OF GATES, N. Y., A CORPORATION OF-NEW YORK.

SIGNALING SYSTEM FOR SINGLETRACK RAILWAYS.

Specification of Letters Patent.

Patented Apr, 8,1919.

Application filed December 7, I915. Serial No. 65,459.

To all whom it may concern Be it known that I, SEDGWICK N. VVIorrr, a citizen of the United States, and a resident of the city of Rochester, in the county of Monroe and State of New York, have invented a new and useful Signaling System for Single-Track Railways, of which the following is a specification.

This invention relates to electrically operated signaling systems for governing railway traffic, and more particularly to block signaling systems for single track railways of the type commonly known as absolute permissive block signaling systems.

Heretofore, signaling systems for single track railways, such as disclosed, for example, in my prior application, Serial No. 753,892, filed March 13th, 1913, have been devised to afford adequate protection against head on and rear end collisions, without unnecessarily restricting the movement of the trains. Although a system such as disclosed in the prior application above mentioned satisfies practically all of the requirements for safety and facility, there is one unusual movementwhich a train may make under certain traflic conditions in which the trains are not as fully protected as they might be. To illustrate, when a train, having entered a stretch of single track between passing sidings, changes the direction of its movement for some reason and attempts to return to the siding from whence it came, the control of the signals is not designed to take care of a move of this character; and it is possible, as fully explained hereinafter, to

have two trains enter the same track section both traveling under caution signals. This invention lSHlIl the nature of an improvement upon the signaling s stem disclosed in my prior application a ove mentioned, and dealsparticularlywith the unusual trainmovement above described One ofthe objects of this invention is to devise a signalin' system for single track railways which wlllaflord adequate protection for a train which has entered a stretch of single track and attempts to make a reverse movement back to the siding from whence it came.

A further object of this invention is to devise/a signaling system for single track railways in which a train making a reverse delay.

A still further object of this inventionis to devise a signaling system which will at tam the above mentioned objects and other objects, which will more fully appear hereinafter, by means of controlling devices and circuits arranged and constructed in accordance with the principles of railway signaling)found to be safe and reliable.

ther objects and advantages will appear as the description of the invention prograsses, and the novel features of the inven tion will be particularly pointed out in the appended claims.

Generally stated, the invention consists in the parts and in the arrangements and combinations of parts, together with the electrical controllin circuits therefor, which are fully set forth hereinafter.

To enable a clear understanding of the nature and utility of this invention, there is illustrated in the accompanying drawing part of a complete signaling system for single track railways, and the circuits and controlling devices with which this invention more particularly deals are combined with this system. It is to be understood, however, that the particular application shown in the drawing is representative of only one physical embodiment of the means contemplated by this invention, and that this invention can be appliedto other signaling systems of ap ropriate construction.

In descri ing the invention in detail, reference is hadto the accompanying drawing, wherein I have illustrated a preferred physical embodiment of my invention, and where in like characters of reference designate corresponding parts throughout the several views, and in which:

The figure is a diagrammatic view of a portion of a stretch of single. track adjacent to one passin siding, and shows the signals, controlling evices and controllingvcircuits therefor, which constitutev a practical signaling system suitable for this portion of the tra-ekway, the system illustrated in this figure being founded on the disclosure in my prior application above mentioned, and being merely a rearrangement of the location of the signals and controlling circuits fully shown and'described in said prior ap plication; and this figure also illustrates the particular features or this invention applied to such a system. I

Referring to the accompanylng drawing, the two track rails 1 and 2 of the stretch of single track adjacent to the passing siding S are divided by insulating joints 3 into a series of track sections A, B, C, D and E, of which there are shown three complete track sections, B, C, and D, with the end portions of the two adjacent track sections A and E. Each of these track sections has a track battery 4 connected across the track rails l and 2 at one end of said section, and at the other ends of said sections, track relays 9 10, 11, 12 and 13 are connected. The track battery 4: and the track relay of each of said track sections, together with the track rails thereof, constitute the well known normally closed track circuit, the operation of which will be clearly understood b those skilled in the art, without further escription. Trafiic over this stretch of single track may be in either direction, as indicated by the arrows X and Y.

At the right-hand end of the track section A is located a signal 6 for governing trafiic in the direction indicated by the arrow X; and located at the right-hand end of the track section B is another signal 7 for governing traffic in the same direction. At the left-hand end of the track section B is located a signal 5 for governing traffic in the direction indicated by the arrow Y, and at the right-hand end of the track section D is located another signal 8 rovernin traflic in the same direction. lhe signa? 6 at the entrance to the stretch of single track, for governing traflic in the direction indicated by the arrow X, is of the type commonly known as an absolute signal; whereas the other signals 5, 7 and 8 are of the type commonly known as permissive signals. The characteristics of these difierent kinds of signals are well known in the art, and it is deemed unnecessary to further discuss the significance of these different si als, or to describe in detail the modeo causing these signals to assume different aspects, so as to enable the engineer to differentiate between them, since it is obvious that this invention is in no wise dependent upon the particular character of signals used.

The signals illustrated are of any well known or suitable type of semaphore signal, adapted for use either in single or double track si aling systems. This type of signal primari y comprises an operating motor of appropriate construction for moving the semaphore from a normal biased position. which may be termed the stop or danger position to one or more operated positions:

and further comprises means to retain the semaphore in its operated position or positions. In the particular embodiment of the invention illustrated, the semaphore signalzare assumed to be three position" signals. that is, these signals have a vertical or degree position, indicating full clear OI proceed at unlimited speed, an inclined or 45 degree position indicating caution or proceed at limited speech and a hori zontal or zero degree position indicating stop or danger. However, this invention is fundamentally in no wise dependent upon three-position signals, and may be used, Without material change or modification, with two two-position signals arranged as home and distant signals, instead of three-position signals.

Associated with each of the signals 5, 6, 7 and 8 is a relay, hereinafter termed a line relay, said relays for said signals being designated 14, 15, 16 and 17 respectively. Associated with each of the signals 6, T and 8 is a relay, hereinafter termed a stick relay, said stick relays for said signals be ing designated 18, 19 and 20; and also associated with each of said signals is a suitable source of electric current, as a battery, sale. batteries being designated 22, 23, and 24. Also associated with each of the signals 6, 7 and 8 is a pole changing circuit controller, which is arranged to be operated in any suitable wa by the move ment of the corresponding signal, said pole changing circuit controllers being designated 25, 26 and 27. Each of these pole changing circuit controllers 25, 26 and 27 is in the position shown in the drawing when the corresponding signal is in its 90 degree or proceed position, and said circuit controller remains in this position even after the respective signal moves to its 45 degree or caution position, but shifts quickly to its other position (indicated by dotted lines on the drawing) when the corresponding signal moves from its caution position to its stop position, said circuit controller remaining in its other position so long as the corresponding signal remains in its stop position. Associated with each of the signals 6, 7 and 8 is another circuit controller, which is represented according to established convention, said circuit controllers being designated 28, 29 and 30, respectively. Each of these circuit controllers is closed durin the movement of the corresponding signa from its vertical proceed position to a position near its caution position, the exact extent of the angular movement of the corresponding signal during which said circuit controller is closed, being dependent upon the operating characteristics of the signal and its controlling relays, the purpose of these circuit controllers being more clearly set forth hereinafter. Associated with the signal 5 is a similar circuit controller 31 which is closed when said signal 5 is in its 90 degree or degree positions or in any intermediate position, but which is open in the positions 01' the signal 5 between 45 de grees and zero degrees.

Although certain relays are herein designated as track relays, certain others as line relays and certain others as stick relays, these designations are chosen merely for the sake of convenience, and it is to be understood that there is no essential difference in reality between the relays so designated, since each of these relays are of any of the well known or ordinary types used for signaling purposes; and any distinction between thcse relays is due, not to differences in their construction, but rather to the different uses to which they are put.

Associated with the signal 5 is a pole changer magnet 32 having two armatures and 34 arranged with appropriate contacts and connections to reverse the polarity of the connection between the battery 21 and a certain circuit hereinafter traced.

Extending the full length of the trackway protected by the signaling system, is a common wire 35, and for convenience, certain of the circuits hereinafter traced will be traced from the common wire 35 at one point back to the common wire at another point, it being obvious that this common wire serves to complete these circuits.

In order to enablea clearunderstanding of the nature and utility of this invention, without, however, attempting to describe in detail the circuits and operation of the single track signaling system shown and described herein, since that signaling system is substantially the same as the system shown and described in my prior application hereinbefore mentioned, a brief general description of the operation of the system disclosed herein will be given, the circuits which have special significance with regard to this invention being set forth in detail.

Considering the operation of the system and disregarding for the present the particular improvemennt embodying this invention, assume that a train enters the stretch of single track from the passing siding S traveling in the direction indicated by the arrow X. When the train enters the track section B, the track relay 10 will be denergized, as will be clearly understood by those skilled in the art of railway signaling, and its armature 40 will drop and in terrupt the circuit which normally energizes the line relay 15, said circuit being as follows:

Circuit number one.

Commencing at the common wire 35, conductors 36, 37 and 38, line relay 15, conductor 39, armature 40 of the track relay 10 in its upper position, conductors 41 and 42, armature 43 of the line relay 16 in its upper position, conductors 44, 45 and 46, upper conducting arm of the pole changing circuit controller 26, conductors 47 and 48 battery 23, conductors 49 50 and 51, lower conducting arm of the pole changing circuit controller 26, conductor 52, armature 53 of the track relay 11 in its upper position, conductor 54, armature 55 of the stick relay 20 in its lower position, conductor 56, armature 57 of the track relay 12 in its upper position and conductors 58 and 59 back to the common wire 35.

The dcnergization of the line relay 15 causes its armature 61 to drop and break the circuit which normally holds the signal 6 in its operated 45 degree position, said circuit for the 45 degree position of the sigus] 6 being as follows:

Uircuz't number two.

Commencing at the battery 22, conductors 48 and 60, armature 61 of the line relay 1;") in its upper position, conductors 62 and 63, signal 6, and conductors 90, 50 and 49 back to the battery 22.

The armature 61 of the line relay 15 also controls the circuit for operating the signal 6 to its 90 degree or proceed position and for holding it in that position, said circuit for the 90 degree position of the signal 6 being as follows:

Oircmlt number three.

Commencing at the battery 22, conductors 48 and 60, armature 61 of the line relay 15 in its upper position, conductors 62 and 64, polar armature 65 of the line relay 15 closed, conductor 66, signal 6 and conductors 90, 50 and49 back to the battery 22.

The entry of the train into the track section B and the consequent deenergization of the track relay 10 causes the armature 73 of said track relay 10 to drop and break the normally closed circuit for energizing the line relay 1.7, said circuit, remembering that part of the train is on the track section A, being as follows:

Oz'rcwlt number four.

Commencing at the common wire 35, conductors 59 and 67, line relay 17, conductor 68, armature 69 of the track relay 12 in its upper position, conductor 70, armature 71 of the track relay 11 in its upper position, conductor 72, armature 73 of the track relay 10 in its upper position, conductor 74, armature 75 of the stick relay 18 in its lower position, conductors 76 and 77, armature 34 of the pole changer magnet 32, conductors 78 and 79, battery 21, conductors 80 and 81, armature 33 of the pole changer magnet 32, conductors 82 and 83; and thence by either one of two paths, one of said paths being along conductor 84, armature 85 of the track relay 9 in its upper position and conductor 86 back to the common wire 35; the other of said two paths being alon conductor 87, armature 88 of the stick re ay 19 in its lower position and conductor 89 to the com mon wire 35.

The deenergization of the line relay 17 auses its armature 61 to drop and interrupt the circuits which operate and hold the signal 8 in its 45 degree and 90 degree positions, said circuits being easily traced by analogy to the circuits numbers two and three, hereinbefore traced, whereby the signal 8 is caused to assume its zero degree or stop position. The deenergization of the line relay 17 also causes its armature 102 to drop and interrupt a circuit, part of which is shown, and which is analogous to the circuit number one for the line relay 15, this circuit serving to normally energize the line relay corresponding to the line relay 17 associated with the next signal to the right of the signal 8 and overning traffic in the direction indicated y the arrow Y. The part of this circuit which is shown is as follows: Commencing at the common wire 35, conductors 91 and 92, armature 93 of the track relay 11 is in its upper position, conductor 94, armature 95 of the stick relay 19 in its lower position, conductor 96, armature 97 of the track relay 12 in its upper position, conductor 98, lower conducting arm of the pole changing circuit controller 27, conductors 51 50 and 49 battery 24, conductors 48 and 47, upper conducting arm of the pole changing circuit controller 27, conductors 99, 100 and 101, armature 102 of the line relay 17 in its upper position, conductors 103 and 104, armature 105 of the track relay 13 in its upper position and conductor 106.

The deenergization of the line relay (not shown), associated with the signal to the right of the signal 8 and governing traflic in the same direction, in turn causes the deenergization of the line relay associated with the next signal to the right of that signal, and so on up to and including the absolute signal for governing the entrance of trains to the stretch of single track from the next passing siding at the right.

As the train in question proceeds and enters the track section C, the track relay 11 is deenergized, and its armatures drop. The dropping of the armature 53 opens another break in the circuit number one for the line relay 15, thereby holding the signal 6 in its sto position. The armature 71 makes another bkeak in the circuit number four of the line relay 17, and thereby holds the signal 8 in its stop position. The dropping of the armature 110 of the track relay 11 breaks the circuit for normally energizing the line relay 16, only part of this circuit being shown and being as follows: Commencing at the common wire 35, conductors 91 and 108, line relay 16, conductor 109, armature 110 of the track relay 11 in its upper position, conductor 111, arn'iature 112 of the track relay 12 in its upper position, conductor 113, ar-- mature 114 of the track relay 13 in its upper position and conductor 115.

The del nergization of the line relay 16 causes its armature 61 to drop and interrupt the circuits, analogous to the circuits numbers two and three, hereinbefore traced, which operate and hold the signal 7 in it, 5 degree and 90 degree positions, thereby causing the signal 7 to assume its zero degree or stop position.

The dropping of the armature 61 of the line relay 16 occurs simultaneously crimmediately after the decnergization of the track relay 11 and the dropping of its armatures; and when the arn'iatures of the track relay 1.1 drop, the armature 122 closes an energizing circuit for the stick relay 19 as follows:

Circuit number Commencing at the battery 23, conductors 48 and 120, circuit controller 29 associated with the signal 7, conductor 121, armature 122 of the track relay 11 in its lower position, conductors 123, and 124, stick relay 19 and conductors 125 and 49 back to the battery 23.

From the foregoing it can be seen that the energization of the stick relay 19 requires that the circuit controller 29 of the signal 7 should be closed; and under the conditions assumed, that is, when the train is travelin in the direction indicated by the arrow )5 the signal 7 is in its 90 degree or proceed position at the time the train in question enters the track section C. Consequently, the energizing circuit number five for the stick relay 19 is closed at or about the same time as the operating circuits for the signal 7 are broken, and since it takes an appreciable time for the signal 7 to assume its stop position, the circuit controller 29 being closed during a portion of this time, said energizing circuit number five is completed long enough to permit the stick relay 19 to 115 raise its armature 127, whereupon a stick circuit for said stick relay 19 is established as follows:

Circuit number sis.

long as the line relay 16 is dencrgized. l/Vhen the armature 131 of the stick relay 19 is raised a shunt comprising conductor 130. armature 131 and conductor 132 is formed for the break in the controlling circuit number one for the line relay 15, which break is controlled by the armature -13 of the limrelay 16, so that, although the line relay U3 is at this time decnergized, as explained hereinbefore, current to energize the line relay 15 can flow through the above mentioned shunt. In this way, the line relay 15 can be energized, and the signal 6 moved. to its caution position while the train in ques tion occupies the track section C, providing the remainder of circuit number one is intact. The signal 6 is moved to its caution position only, instead of to its full clear 90 degree position by reason of the movement of the pole changing circuit controller 2;; by the signal 7 to its reverse dotted line p0stion, when said signal 7 assumes its stop position, and this causes a reversal of the direction of flow of current in the line relay 15, so that, while its armature 61 will be raised to close circuit number two for the 47) degree position of the signal 6, the polar armature 65 is moved to its open position to interrupt circuit number three for the 91) de es position of said signal 6.

he clearing of the signal 6 to its 15 degree position as soon as the train, moving in the direction indicated by the arrow X, passes entirely into the track section C, is characteristic of the system disclosed in my prior application hereinbefore mentioned, and is also characteristic of the particular improvements in this system disclosed in my application, Serial No. 65,458, filed of even date herewith, which improvements are intended to prevent the occurrence of the same undesirable condition hercinbefore described arising from the unusual reverse movement of the train. In the arrangement of controlling circuits shown and described in my above mentioned prior applications, the intermediate signals corresponding to the sig nals 7 and 8 governing trafiic in opposite directions are located opposite to each other, so that-the signal 6, in being responsive to the presence of a train traveling in the direction indicated by the arrow X anywhere between the signal 6 and the signal 7, is also responsive to the presence of such a train anywhere between said signal 6 and its opposing signal. In certain arrangements or locations of signals, however, it has been found expedient to locate corresponding intermediate signals governing trafiic in opposite directions in a staggered relation, that is, in the relative positions illustrated in the accompanying drawing; and in systems in which the signals are arranged in this staggered relation, according to the practice best known to me, the signal 6 does not control asfar as its opposin signal 8, in fact, not even beyond the sigma 7; that is, a train anywhere in the track section B will cause said signal 6 to assume its stop position, even though said train is traveling in the direction indicated by the arrow X and the stick relay 19 is energized, but a train in the track section C will not cause the signal 6 to assume its stop position. Consequently, in the unusual condition of traiiic resulting from the peculiar reverse movement hereinbefore described, a train, traveling in the direction indicated by the arrow X, after having entered the track section E and then reversed the direction of its movement, would have to move clear back into the track section B before it would cause the signal 6 to assume its danger position. For this reason it is necessary to make the control of the signal 6 extend to and include the track section D, and that this is a feature of the controlling circuits illustrated can be seen by referring to circuit number one for the line relay 15, which shows that said line relay 15 cannot be energized until the train has left the track section D, and the armature 57 of the track relay 12 has resumed its upper position. As soon, however, as a train moving in the direction indicated by the arrow X has entirely left the track section D, the line relay 15 may be energized, although the armature 114 of the track relay 13 breaks the circuit for the line relay 16 and causes the deenergization of said line relay 16, by reason of the fact that the stick relay 19 is energized and the armature 43 of the line relay 16 is shunted.

Referring now more particularly to the features of the arrangement of devices and controlling circuits therefor shown in the accompanying drawing which embody this invention, it is assumed that a train has passed along the portion of trackway shown in the direction indicated by the arrow X and is in the track section E. Under these conditions the signal 7 will be in its zero degree or stop position, the signal 6 in its 45 degree or caution position, and the stick relay 19 energized. Regarding the signal 8, it can be seen. from circuit number four, hereinbefore traced, that the energization of the line relay 17 which controls this signal 8, depends upon the armature 85 of the track relay 9 and-the armature 88 of the stick relay 19, these armatures and their associated conductors being arranged in parallel. so that with either.of these armatures closed, current will flow fromthe battery 21 to the line relay 17 assuming, of course, that the track sections B, C and D are not occupied. The direction of flow of current in the circuit number four through the line relay 17 depends upon the pole changer magnet 32, which in turn is controlled by the circuit controller 31 of the signal 5, and

other devices to the left, which are not necessary to consider. As much of the controlling circuit for the pole changer magnet 32 as 18 shown is as follows: Commencing at the common wire 35, conductors 36, 133 and 134, pole changer magnet 32, conductor 135, circuit controller 31, conductor 136- and through other controlling devices at the left, as set forth in my prior application above mentioned, through a battery and back to the common wire 35. The signal 5 is con trolled by the line relay 14, which in turn is controlled by the track relay 9, the cir- -xcuit for the line relay 14, that is, as much of this circuit as is shown, being: from the common wire-35, conductors 36, 133 and 137, line relay 14','conductor 138, armature 139 of the track relay 9, conductor 140 and thence through other controlling devices at the left and a battery back to the common wire 35. The circuits for controlling the signal 5 are similar to circuits numbers two and three and can be easily traced by analogy. With conditions as just described, assume that a following train enters the track section A. As far as the controlling circuit for the line relay 17 is concerned, its polarity is reversed by reason of the fact. that the signal 5 assumes its stop position and breaks the circuit for ener izing the pole changer magnet 32 at the circuit controller 31. This by itself would cause the signal 8 to assume its 45 degree or caution position, which, however, would not be sufficient to protect the first train in the track section E in making a reverse movement back to the siding S, since the second train in the track section A might properly accept the signal 6 in its caution position, and then two trains moving in opposite directions would enter the same portion of single track between two opposin signals,

In the system embodyin t is invention, however, the stick relay 19 is energized and its armature 88 is in its upper position. thereby interrupting one path for the flow of current in circuit number four from the battery 21 to the common wire 35. Hence, if a following train enters the track section A, its presence causes the deenergization of the track relay 9 and the dropping of the armature 85, and this armature 85 interrupts the other remaining path of the flow of current in said circuit number four, with the result that all supply of current to the line relay 17 is out off, and the signal 8 will assume its stop position.

One important feature of this invention consists in arranging the controlling circuit for the line relay 17, which controls the signal 8 and which is drawn in heavy lines in the drawin so that, when the stick relay 19 is energlzed by the passage of a train traveling in the direction indicated by the arrow X, said line relay 17" will be subject to the control of the track relay 9 of the track section A, or of the track relays of other track sections to the left. It should also be noted that the stick relay 19 performs the function of selectively determinin whether the stop indication of the signa 8 shall be controlled by the track relay 9 of the track section A or by the track relays 10, 11 and 12 of the track sections B, C and D; and this selective action of the stick relay 19 is necessary, since for trains traveling in the direction indicated by the arrow Y the stop indication of the signal 8 need be under the control of the track sections 13, C and D only, in conjunction with the line relay 16. Whereas for trains traveling in the direction indicated by the arrow X and making the reverse move of the character before described, the stop indication of the signal. 8 should be controlled by the track section A, as well as the track sections B, C and D.

one way of accomplishing the result above described is illustrated in the accompanying drawing; but, obviously, other modified arrangements of controlling circuits can be used: and in my co-pending application, Serial No. 65,458, filed the same date herewith, i have illustrated and described other ways of accomplishing the same result. I wish it to be understood that I contemplate the use of any one of the di-lferent arrangements of controlling circuits shown in said application in every case Where such arrangements are applicable, including a system employing staggered intermediate signals. It is considered unnecessary to show in detail the circuits showing the application of said modifications to the system having staggered intermediate signals, since such changes can be easily determined by one skilled in the art of railway signaling from the disclosure in said application and the disclosure herein.

Another feature of the controlling circuits shown and described relates to the checking of the operation of the stick relays, and particularly the dropping of the armatures of said stick relays, since it may happen that the armatures of one of the stick relays will, for some reason, fail to drop when it should. The necessity for such checking will be apparent from a simple illustration. Assume a train is traveling in the direction indicated by the arrow Y from the track section E into the track section D. Under these conditions the energizing or pick up circuit for the stick relay 20 is established, said circuit being as follows:

ductor 146, armature 147 of the track relay 12 in its lower position, conductor 148, ar-

mature 149 of the track relay 13 in its lower position, conductors 150 and 151, stick rclay 20 and conductors 152 and 49 back to the battery 24.

The armature 154 of the stick relay 20 closes a shunt comprising conductors 153, said armature 154 and conductor D55 for the armature 102 and its cooperating contacts controlled by the line relay l7; and consequently, although the line relay 17 may be deenergized and its armature 102 in its lower position, the line relay controlling the next signal to the right corresponding to the signal 8 and governing traiiic in the direction indicated by the arrow Y, may be energized. Suppose the armatures of the stick relay 20 do not drop when they should, and that another train, traveling in the direction indicated by the arrow X enters the track section B. The denergization of the track relay 10 and the dropping of its armature 40 would interrupt the circuit number four for energizing the line relay 17, as explained hcreinbefore; and the armature 102 of said line relay should drop and cause the decnergization of the line relay controlling the signal next to the right of the signal 8 and governing ti'aflic in the same direction; but, since the armature 154 of the stick relay 20 is assumed to have remained in its upper position, the armature 102 of said line relay 17 is shunted, and the signal to the right of the signal 8 does not assume its danger position, as it should. To avoid this objection, the controlling circuit for the line relay 15 is arranged to include the armature 55 of the stick relay 20 in its lower position, so that, if the armatures of said stick relay should improperly remain in their upper position, the signal 6 could not assume its proceed position. In the same way, circuit number four for the line relay 17 includes the armature 75 of the stick relay 18 in its lower position. In short, the circuit for controlling each line relay associated with each signal includes an armature in its lower po sition controlled by the stick relay associated with the next opposing signal.

Various changes may bemade in the particular arrangements of circuits and controlling devices shown and described without departing from the invention or the physical embodiment thereof illustrated, and also this invention may be applied to other signaling systems. Also, although the par: ticular embodiment of the invention shown is designed to be operated by direct current, simple modifications apparent to those 7 skilled in .the art of railway signaling, may

be made i where alternating current may be used as an operating medium. The number oi track sectionsinto which the stretch. of single track may be divided may be different according to different conditions Without afi'ecting the-applicationrot this 'iIILVQI1- tion; and other signals for protecting the sidings, preliminary sections, and other expedients known in the art of railway signaling may be combined with this invention.

Although I have particularly described the construction of one physical embodiment of my invention, and explained the operation and principle thereof; nevertheless, I desire to have it understood that the -form selected is merely illustrative, but does not exhaust the possible physical embodiments of the idea of u'ieans underlying my inven tion.

What I claim new and desire to secure by Letters Patent of the United States, is:

1. In a signaling system for railways, in combination: a stretch of trackway divided into electrically isolated track circuited sections, each having a track relay; a first and a second signal for governing traffic in one direction over said stretch, a third signal located beyond said second signal for governing trafiic in the opposite direction; a circuit for controllin said third signal; a circuit controller inc uded in said circuit; a normally closed shunt for said circuit controller controlled by the track relay of a track section in advance of the third signal and beyond the first signal; a second circuit controller associated with said second signal and closed thereby during a portion of the movement thereof from its normal position; a,relay for opening said first circuit controller when energized; and an energizing circuit for said relay controlled jointly by said second circuit controller and the track relay of the section protected by said second signal.

2. In a signaling s stem for railways, in combination: a stretch of trackway divided into electrically isolated track circuited sections, each having a track relay; a signal at one end of said stretch for governing traliic in one direction; two intermediate signals arranged in staggered relation adjacent to said end of said stretch; a circuit for controlling the intermediate signal opposing said first signal; a circuit controller con trolled by the track relay of the section preceding the section protected by said first signal and included in said circuit; a normally closed shunt for said circuit controller; and means set into operation by the movement of a train in the direction of traflic governed by said first signal for opening said shunt.

3. In a signaling system for railways, in combination: a stretc of trackway divided into electrically isolated track circuited sections, each having a track relay; a signal at one end of said stretch for governing trafiic in one direction; a second signal for governingtrafi ic in the same direction; a third signal succeeding said second signal for governing traflic inthc opposite irection;

' ing a polarized relay for controlling said first signal; a circuit for said relay; a pole changer controlled by said second signal for reversing the polarity of said circuit; means governed by the track relay of a track sec tion in advance of the second signal and beyond the third signal for exerting a controlling infiuence tending to open said circuit when said advance track section is occupied; a device set into operation by a train traveling in the direction of trafiic governed by the first and second signals for rendering said means ineffective; and means controlled by the track relays of the sections between said second and said third signal for opening and closing said circuit accordingly as said sections are occupied or unoccupied by another train.

'4. In a signaling system for railways, in combination: a stretch of trackway divided into electrically isolated track circuited sections, each having a track relay; a signal at one end of said stretch for governing trailic in one direction; a second signal for govcrntrafiic in the same direction; a third sigsucceeding said second signal for governing trailic in the opposite direction a polarized relay for controlling said first signal; a circuit for said relay; means controlled by said second signal for reversing the polarity of said circuit; means controlled by the track relays of the sections between said second and said third signal for opening and closing said circuit accordingly as said sections are occupied or unoccupied by another train; a second circuit for controlling said third signal; a circuit controller governed by the track relay of the section preceding the section protected by said first signal for opening and closing said second circuit; a normally closed shunt for said circuit controller; and means set into operation by the movement of a train in the direction of traffic governed by said second signal for opening said shunt.

5. In a signaling system for railways, in combination: a stretch of trackway divided into electrically isolated track circuited sections. each having a track relay; a first and a second signal for governing traflic along said stretch in opposite directions; an intermediate signal located between said signals for governing traflic in the same direction as said first signal; a circuit for controlling said first signal governed by the track relays of all of said sections between said first signal and said second signal; a second circuit for controlling said second signal; a circuit controller included in said second circuit and governed by the track relay of a section preceding the section, protected by said first signal; a normally closed shunt for said circuit controller; a second circuit controller operated by said intermediate signal and closed during'a portion of the movement thereof from its normal position; a relay; an energizing circuit for said relay controlled jointly by said second circuit controller and the track relay of the section protected by said intermediate signal; and means operated by the energization of said relay for opening said shunt.

6. In a signaling system for railroads, the combination with a stretch of single track and a passing siding. of a signal located at a distance from one end of the siding and governing traflic away from the siding, a second signal located beyond the first signal and governing trafiic toward the siding, means for causing the stop aspect of the second signal to be dependent upon the presence or absence of a train on the track between said signal and the siding, and means set into operation by a train moving in the direction away from the siding for causing the stop aspect of said second signal to be also dependent upon the presence or absence of a train on a predetermined portion of the track extending alongside of the siding.

7 In a signaling system for railroads, the combination with a stretch of single track and a passing siding, of a signal located at a distance from one end of the sidin and governing trafl'ic away from the sidlng, a second signal located beyond the first signal and governing trafiic toward the siding, and controlling circuits and apparatus for governing the second signal and adapted to cause the limits of control for the stop aspect of that signal to extend up to the adjacent end of the siding when a train moves in the direction toward the siding and to extend up to a farther point between the ends of the siding when a train moves in the 0pposite direction.

8 In a signaling system for railroads, the combination with a stretch of single track and a passing siding, of a signal located at a distance from one end of the siding and governing trafi'ic away from the siding, a second signal located beyond the first signal and governing trafiic toward the siding, a circuit for controlling the stop aspect of the second signal which is controlled by the track circuit sections between that signal and the adjacent end of the siding and Which includes two branches in multiple,

means governed by a track circuit section of the track located between the ends of the siding for opening one branch of said cir cuit when that track section is occupied, and means rendered active by a train traveling in the direction away from the siding for opening the other branch of said circuit.

9. In a signaling system for railroads, the combination with a stretch of single track and a passing siding, of a signal lo ated at a distance from one end of the siding and governing trafiic away from the siding, a

second signal located beyond the first signal and governing traflic toward the siding, a signal circuit for controlling the sto aspect of said second signal and controlle by the track circuit sections of the track between said signal and the adjacent end of the siding, a circuit controller included in said circuit, said circuit controller being governed by a track circuit section adjacent to the siding and between the ends thereof and being open when that track section is occupied, a normally closed shunt for said circuit controller, and means for opening said shunt when a train. travels in the direction away from the sidin and for maintaining it open until such train has advanced a predetermined distance from the siding and beyond the second signal.

10. In a signaling system for railroads, the combination with a stretch of track located adjacent to a passing sidin and divided into track circuit sections, 0 a signal located at a distance from one end of the siding and governing traffic toward the siding, a circuit for controlling said signal having two branches in parallel, one of said branches including a front contact of the track relay associated with a: track section adjacent to the siding and between the ends thereof, a normally denergized stick relay, controlling circuits tor said stick relay governed by certain track relays of the stretch and adapted to energize said relay when a train travels in the direction away from the siding toward the signal and to maintain said relay energized until such train has advanced a predetermined distance from the siding, and a normally closed circuit controller included in the other branch of said circuit and open when said stick relay is energized.

11. In a signaling system for single track railroads provided with track circuit sections, the combination with a stretch of single track between passing sidings, or ins termediate signals located 111 staggered relation at different points along the stretch, and controlling circuits and apparatus for said intermedlate signals acting when a. train enters the stretch to cause each oi the opposing intermediate signals to indicate stop and also to permit each opposing intermediate signal to assume a proceed aspect as each signal is successively pamed by saidtrain.

12. In a signaling system for single track railroads provided with track circuit secs tions, the combination with a stretch of single track and a passing siding, a first signal and a second slgnal located at diflerent distances from one end of the siding and governing traflic in opposite directions, a signal circuit for controlling the stop aspect of the second signal remote from the siding, a device associated with the first signal and responsive to the direction of movement of trains, said device being automatically changed from its normal condition when a train travelsin the direction of traffic governed by the first signal and being maintained in its changed condition until such train has advanced to a predetermined point in advance of the first signal and beyond the second signal, a circuit controller included in the signal circuit for the second signal and opened when said device is changed from its normal condition, and a shunt for said circuit controller interrupted when a train occu ies a portion of the track adjacent to the siding and between the ends thereof.

13. In a signaling system for single track railroads provided with track circuits, the combination with a first signal, of two other signals arranged in staggered relation in advance of the first signal and governing trafiic in opposite directions, a stick relay associated with each signal and automatically changed from its normal condition when a train travels in the direction of traflic governed by the corresponding signal, a signal circuit for controlling each signal, the signal circuit for the first signal including a back contact of the stick relay associated with the opposing signal farthest from the first signal, and the signal circuit for the signal farthest from the first signal including the back contacts of the stick relays associated with the other two signals, and means controlled by a track circuit in the rear of the first signal fior normally establishing a shunt for the back contact of the stick relay of said first signal.

14. Ina signaling system for single track railroads having a passing siding, the combination with a first signal adjacent to the passing siding for governing traflic away from the siding, of two other signals arranged in staggered relation in advance of the first signal and governing traflic in opposite directions, the other signal nearest the first signal governing traflic in the same direction as the first'signal, a stick relay associated with the first signal and automatically changed from its normal condition by a train traveling in the direction of tralfic governed thereby, and a signal circuit for the opposing signal farthest from the first signal including a normally closed contact operated by said stick relay.

15. In a signaling system for single track railroads provided with track circuits, the combination w-ith' a first signal for governing traific in one direction, of two other signals arranged in staggered relation in advance of the first signal and governing trafiic in opposite directions, the other signal nearest the first signal governing trafiic in the same direction as the first signal, a stick relay associated with each signal and automatically changed from its normal condition when a train travels in the direction of traflic governed by the corresponding signal, a signal circuit for controlling the op posing signal farthest from the first signal including the back contacts of the stick relays associated with the other two signals, and means controlled by a track circuit in the rear of the first signal for normally establishing a shunt for the back contact of the stick relay of said first signal.

16. In a signaling system for a single track railroad divided into track circuit sections and having a passing siding, the combination with a signal located at a distance from one end of the siding and governing traflic toward the'siding, a signal circuit for controlling said signal governed by the track circuit sections between the signal and the adjacent end of the siding, said signal circuit also including a front point of an armature of the track relay of a track section adjacent to the siding and between the ends thereof, a normally closed shunt for said front point and armature, and means set into operation by the movement of a train in the direction away from the siding for opening said shunt and for maintaining it open until such train has advanced a predeter mined distance from the siding.

17. In a signaling system for a single track railroad divided into track circuit sections and having a passing siding, the combination with a signal located at a distance from one end of the siding and governing trafiic toward the siding, a signal circuit for controlling said signal governed by the track circuit sections between the signal and the siding, said signal circuit including two branches in multiple, one of said branches including a front contact of the track relay of a track section located adjacent to the siding and between the ends thereof, a cir cuit controller included in the other of said branches, and electrically operable means controlled by certain track circuit sections for causing said circuit controller to be closed when a train travels in the direction toward the siding and to be open when a train travels in the opposite direction.

18. In a signaling system for a single track railroad divided into track circuit sec-' tions and located adjacent to a passing siding, the combination with a signal located at a distance from one end of the siding and governi trailic toward the siding, of a polarize line relay for controlling said signal, a line circuit includin said line relay and controlled by the trac circuit sections between the signal and the adjacent end of the siding, said line circuit also including a front contact of the track relay of a track section adjacent to the siding and between the ends thereof, a shunt for said front contact, means responsive to the direction of movement of trains for causing said shunt to be open only when a train-travels in the direction away from the siding, and means responsive to the presence of a train on a portion of the track in advance of the si nal and beyond the adjacent end of the si ing for controlling the polarity of said line circuit.

19. In a signaling system for a single track railroad provided with a passin siding, the combination with a first signal located at one end of the siding and governin traflic in the direction away from the si ing, a first and a second intermediate signal arranged in staggered relation in advance of the first signal, the second intermediate sigso nal being located farthest from the siding, and means for causing the limits of the stop control for the first signal to extend up to the second intermediate signal for trains traveling in the direction of trafiic governed by the first signal and to extend up to a int beyond the second intermediate signa for trains traveling in the opposite direction.

20. In a signalin system for a single track railroad provided with a passing siding, the combination with a first signal 10- cate'd at one end of the siding and governing trafiic in the direction away from the siding, a first and a second intermediate si nal arranged in staggered relation in ad vance of the first signal, the second intermediate signal being located farthest from the siding, means for causin the limits of thestop control for the first signal to extend up to the second intermediate signal for trains traveling in the directio'n of traflic governed by the first signal and to extend up to a'point beyond the second intermediate signal for trains traveling in the opposite direction, and means for causing the limits of the stop control for the second intermediate signal to extend to the adjacent end of the siding for trains traveling in the direction toward the siding and to extend to a farther point between the ends of the siding for trains travelin in the opposite direction away from the si mg.

21. In a signalin system for a single track railroad divid into track circuit sections and having a passing siding, the combination with a first signal located at one end of the siding governing trafiic away from the sidin a second signal and a third signal arrang in staggered'relation in advance of the first signal, the third signal being farthest from the siding, a line relay for eontrollin each signal, a line circuit for the line re ay of'the second si al controlled by the track circuit sections o a certain portion of thetrack in advance thereof and ex- 126 tendin beyond the third signal, a circuit control or opened when the line relay of the second signal is denergized, a shunt for said circuit controller, a stick relay for closing said shunt when a train travels in the direction of traffic governed by the second signal, us], and means set into operation when said a line circuit for the line relay of the first stick relay is energized for placing the line 10 signal including said circuit controller and circuit for the thlrd signal also under the the front contacts of the track relays of the control of a track circuit section located adtrack sections between the second and third jacent to the siding and between the ends signals, a line circuit for the line relay of the thereof.

third s' a1 controlled by the track circuit sections etween that signal and the first sig SEDGWICK N. WIGHT.

Copies 0! thin patent may be obtained for five cents each, by droning the "comiuioner 02 Intake, Washington, D.- 0. 

